CHAPTER 3 LCD CONTROLLER/DRIVER
User’s Manual U18438EJ2V0UD
33
3.8 Display Modes
3.8.1 Static display example
Figure 3-13 shows how the three-digit LCD panel having the display pattern shown in Figure 3-12 is connected to
the segment signals (S0 to S23) and the common signal (COM0). This example displays data "12.3" in the LCD panel.
The contents of the display data memory (addresses 00H to 17H of LCDSEG) correspond to this display.
The following description focuses on numeral "2." ( ) displayed in the second digit. To display "2." in the LCD
panel, it is necessary to apply the select or deselect voltage to the S8 to S15 pins according to Table 3-6 at the timing
of the common signal COM0; see Figure 3-12 for the relationship between the segment signals and LCD segments.
Table 3-6. Select and Deselect Voltages (COM0)
Segment
S8 S9 S10 S11 S12 S13 S14 S15
Common
COM0 Select
Deselect
Select
Select Deselect Select Select Select
According to Table 3-6, it is determined that the bit-0 pattern of the display data memory locations (08H to 0FH of
LCDSEG) must be 10110111.
Figure 3-14 shows the LCD drive waveforms of S11 and S12, and COM0. When the select voltage is applied to
S11 at the timing of COM0, an alternate rectangle waveform, +V
LCD
/
−
V
LCD
, is generated to turn on the corresponding
LCD segment.
COM1 to COM3 are supplied with the same waveform as for COM0. So, COM0 to COM3 may be connected
together to increase the driving capacity.
Figure 3-12. Static LCD Display Pattern and Electrode Connections
S
8n+3
S
8n+2
S
8n+5
S
8n+1
S
8n
S
8n+4
S
8n+6
S
8n+7
COM0
Remark
n = 0 to 2